Radio loud-speaker



July 22, 1930. c. MCCONNELL 1,771,266

RADIO LOUD SPEAKER Filed March 26, 1929 Patented July 22, 1930 PATENTOFFICE CHARLES MccormEL or NEW YORK, N. Y.

namo LOUD-SPEAKER Application filed March 26, 1929. Serial No. 349,950.

This invention relates to new and useful im rovements in loud speakers.

, he invention has for an object the provision of a device of the classmentioned 5 which is of simple durable construction, de-

pendable in use and eificient in action, and which can be manufacturedand sold at a reasonable cost. I It is proposed to use a soundreproducing l diaphragm having a plurality of slightly spaced soundboardsections attached upon a membrane, each of the sections consisting of afiat thin wooden strip, and a vibration spreader attached on the rear ofthe sound 15 board sections and connected with a loud speakerelectro-magnetsupported on a frame arranged for also supporting the saidmembrane. I

This construction derives particular ad- 3 vantages in that vibrationsset up by the electro-magnet and communicated to the diaphragm cause thesound board sections of the diaphragm to vibrate and reproduce the soundwith a minimum amount of distortion by reason of the sound boardsections being capable of deflecting independently from each other. Ithas been found that where the sound board of one complete piece, dis- 1tortion is quite probable but with the board of several sections thedistortion is materially reduced. i In the accompanying drawing forminga material part of this disclosure Fig. 1 is a front elevational View ofa device constructed according to this invention. Fig. 2 isan endelevational view of Fig. 1. Fig. 3 is an enlarged rear'elevational viewof Fig. 1. e

Fig. 4 is a vertical sectional View taken on the line H of Fig. 3.

Fig. 5 is a fragmentary detail sectional view of a portion of Fig. 4.

Fig. 6 is a sectional 66 of Fig. 3. e

Fig. 7 is a fragmentary view of a portion of Fig. 3 disclosinga modifiedform thereof. The reference numeral 10 indicates generally a frameconsisting of a top longitudinal member 11, bottom longitudinal member50 12 and side vertical members 13. A means view taken on the line 14for supporting a loud speaker electromagnet is secured upon the rear ofthe frame 10 and supports a loud speaker electromagnet 15. Thiselectro-magnet is connected with a sound reproducing diaphragm 16. Themeans 14 for supporting the loud speaker electro-magnet consist of apair of spaced longitudinal strips 17 attached upon the rear of theframe 10 and joined by a vertical strip 18 offset from the verticalcenter of the longitudinal strips. The loud speaker electro-magnet isattached upon a support bracket 19 supported upon the said strips 17 and18. The vibration core of the loud speaker is indicated by numeral 20and is connected with a needle post 21 which projects into a chuck 22secured on a fiat semiring vibration distributor 23 by a nut 24. Thechuck 22 serves to adjust the length of the needle post. I 1 The soundreproducing diaphragm 16 consists of a membrane 25 stretched tightlyacross the front of the frame 10 and held in position by molding 26. Aplurality of slightly spaced sound board sections 27 are attached behindthe rear face of the membrane 25, each of the sections consisting of aflat thin wooden strip. A vibration spreader is connected onthe rearfaces of the sections 27 and consists of the said semi-ring vibrationdistributor 23 having spaced radial support strips 23 attached upon itsfront face, and radial vibration transmitting ribs 28 are attached uponthe front of the strips and upon the rear of the said sound boardsections 27. Preferably the ribs, the semi-flat ring, and the radialsupport strips should be of Wood, and glue used for fastening theseparts as, before described. The free extremitiesof the ribs 28 should bereduced, as indicated by reference numeral 29.

In the modified form of the device illustrated in Fig. 7, a sound boardsection connector 30 has been illustrated engaged upon one of the soundboard sections 27. A plurality of said connectors should be used uponall of the sections. Each of these connectors consists of a portion 31disposed between adj acent edges of adjacent sections 27 and having anintegral rear flat portion 32 extending over one of the sections 27 andformed with an inclined slot 83 thru whicn a locking screw 3 passes,This locking screw engages within the section 27 and serves to hold theconnector in fixed positions. The connector should preferably be made ofwood.

In operation of the device, the operation of the loud speakerelectro-magnet 15 causes its core 20 to vibrate which vibrations aretransmitted to the distributor 23. The chuck 22- may be loosened forchanging the length of the needle post 21 to arrange for the propertransmission of vibrations. Vibrations communicated with the distributor23 move on to the support strips and to the vibration transmitting ribs28. The vibrations of the ribs 28 are next communicated to the soundboard sections It is pointed out that the sections 27 may individuallyvibrate the bend as controlled by forces applied to these sections. Suchindividual vibration of the sepa rate boards tend to reduce distortionwhich would be likely if one portion of the sound board attempted tovibrate and force other portions into vibrations not in harmony with itsattempted movement. Much better results are obtained by the use ofindividual vibration sections.

The length of ribs 28 are so arranged as to allow the dilferentfrequency in the notes to be emphasized by the individual ribs due tothe gradual variations in the length of the aid ribs. The short ribsbring out the high frequency notes whereas the long ribs 28 bring outthe base or low frequency notes.

The connectors 30 may be moved for connecting adjacent sections. Suchmotion is permitted by first loosening the screws 34 and then movin theconnectors against the adjacent sound board sections. A tightening ofthe screws hold the connectors in contact. This permits a control of thevibrations of the various sections communicating with each other andadjustments may be made for obtaining the most satisfactory tones bymoving several or all of the connectors into operative positions.

While I have shown and described the preferre'l embodiment of myinvention, it is to be understood that I do not limit myself to theorecise construction herein disclosed and the right is reserved to allchanges and modifications coming within the scope of the invention asdefined in the appended claims.

Havi g thus described my invention, what I claim as new, and desire tosecure by United States Letters Patent is 1. A loud speaker, comprisinga frame, a diaphragm attached on the front thereof, a loud speakermounted on the rear of the frame and a vibration spreader connectedbetween the loud speaker and diaphragm, said diaphragm consisting of amembrane and individual sound boards.

2. A loud speaker, comprising av frame, a

diaphragm attached on the front thereof, a loud speaker mounted on therear of the frame, and a vibration spreader connected between the loudspeaker and diaphragm, said diaphragm consisting of a membrane andindividual sound boards, said vibration spreader including a flatsemi-ring vibration distributor connected with a needle post, and radialvibration transmitting ribs.

3. A loud speaker, comprisin a frame, a diaphragm attached 011 the frontthereof, a loud speaker mounted on the rear of the frame, and avibration spreader connected between the loud speaker and diaphragm,said diaphragm consisting of a membrane and individual sound boards,said vib 'ation spreader including a fiat semi-ring vibrationdistributor connected with a needle post, and radial vibrationtransmitting ribs, the needle post being of two sections adjustablyconnected.

at. In a loud speaker, a diaphragm consisting of a meml'n-ane and aplurality of slightly spaced sounding board sections. a fiat semi-ringvibration distributor for connection with a loud speaker electro-magnet,and radial vibration transmitting ribs connected between the distributorand the board sections 5. In loud speaker, a diaphragm consisting of amembrane and a plurality of slightly spaced sounding board sections, aflat semiring vibration distributor for connection with a loud speakeractuating mechanism spaced from the rear of theboard sections, andradial vibration transmitting ribs connected between the distributor andthe board sections.

6. In a loud speaker, a diaphragm consis ing of a membrane and aplurality of sli 'htly spaced sounding board sections, a flat semi-ringvibration distributor for connection with a loud speaker actuatingmechanism spaced from the rear of the board sections, and radialvibration transmitting ribs connected between the distributor and theboard sections, said board sections having soundboard section connectorsfor vib 'ationally connecting the sections.

7. In a loud speaker, a diaphragm consisting of a membrane and aplurality of slightly spaced sounding board sections, a flat semi-ringvibration distributor for connection with a loud speaker actuatingmechanism spaced from the rear of the board sections, and radialvibration transmitting ribs connected between the distributor and theboard sections, said board sections having sound board sectionconnectors for vibrationally connecting the sections, each connectorconsisting of a portion disposed between adjacent edges of adjacentsections, and an integral flat portion extending over one sect-ion andadj ustably mounted.

8. A loud speaker, comprising a frame, a

diaphragm attached on the front thereof, a loud speaker mounted on therear of the frame, and a vibration spreader connected between the loudspeaker and diaphragm, said diaphragm consisting of a membrane andindividual sound boards, said vibration spreader including a flatsemi-rin vibration distributor connected with a need e post, and radialvibration transmitting ribs, said transmitting ribs arranged in palrs,each pair being of different length.

9. A loud speaker, comprising a frame, a diaphragm attached on the frontthereof, a loud speaker mounted on the rear of the frame, transmittingribs connected between the loud speaker and diaphragm, said diaphragmconsisting of a membrane and individual sound boards, said transmittinribs arranged in pairs, each pair being of di erent length, some of saidtransmitting ribs connect a plurality of the said individual soundboards.

In testimony whereof I have aflixed my signature.

CHARLES MOCONNELL.

